1) HA Power supplies, availability calculations -- Paul Bellomo
2) Muons from PC3 -- Lew Keller
3) Progress on ATF2 quads -- Cherrill Spencer
Paul presented calculation of availability of ILC power supply system if an
ATF2 HA PS design would be applied to ILC and compared it with non-redundant
system and fully redundant system.
The availability, for the considered parameters increased from 0.8 for non-redundant system, to 0.91 for a system like the one proposed for ATF2 (redundant individual power supplies). The hot replacement of power supplies did not increase availability significantly. The redundant bulk power supplies increased it to 0.93. Making the controllers redundant increased availability to more than 0.98.
Updated version of this talk was presented at the ATF2 project meeting.
Lew considered production of muons at protection collimator PC3, 1225 m from the IP, and presented the muon rate at the detector, assuming either a 18 m long or a 5 m long single magnetized muon wall (at least a 5 m magnetized wall is required for personnel protection [Machine-Detector Interface Workshop, Jan. 6-8, 2005]). It is assumed that 0.001 of the beam is lost in the BDS collimator sections and that 15% of the muons in the detector come from PC3. Simulations show that for 250 GeV beam and 5 m magnetized wall there are 64 muons per 200 bunches (the TPC sensitive time) from PC3. Thus, the for the minimum configuration of a single 5 m wall, the allowed losses in the collimator section are no more than 2.e-5 (which would give less than 10muons/200 bunches in the TPC -- this detector tolerance needs to be clarified with the MDI group). For detectors that can resolve single bunches, the allowed losses are greater, as shown in the table.
Cherrill presented progress of manufacturing of the ATF2 quads at IHEP, China. The first magnet was assembled and magnetic measurements were performed.
Andrei Seryi, 02/07/06